Turquoise-colored mushrooms? How cool is that? I’ve been looking for these for several years, and although
I have often found the mycelium on wood—a blue-green stain—I have seen the fruiting bodies
only twice, on Mt. Watatic and Oak Hill, both in Massachusetts. Returning to one of the places where I had seen
the mycelium, the wood
had been removed, apparently by someone who recognizes its wood carving value. It is used in creating intarsia,
an inlaying process using tiny, thin veneers similar to parquetry.
So I am grateful to Amanda Felegie for sending in the photo she took at
Ricketts Glen State Park in Pennsylvania.

Identification: This fungus appears on decayed hardwood, principally oak,
spreading deep into the wood. It has small cup-shaped asocarps attached to the wood by a stemlike base called
the stipe. The fruiting bodies rarely exceed ¾" (1.9 cm) in size. The
fruiting bodies appear only on wood that is decayed enough to be free of bark. Michael Kuo’s site,
MushroomExpert.com,
points out that these could
be either Chlorociboria aeruginascens or Chlorociboria aeruginosa. The only way to differentiate between them is by comparing the spore size, which are a microscopic 5-8 µm by
0.7-2.8 µm, smaller than those of C. aeruginosa.

Roughly 75 people in North America are poisoned each year by mushrooms, often from eating a poisonous species that resembles an edible species. Though deaths are rare, there is no cure short of a liver transplant for severe poisoning. Don’t eat any mushroom unless you are absolutely certain of its identity! Please don’t trust the identifications on this site. We aren’t mushroom experts and we haven’t focused on safely identifying edible species.